Incandescent body for electric glow-lamps.



7 NITED STATES PATENT OFFICE.

ALEXANDER JUST, OF VIENNA, AUSTRIA-HUNGARY.

INCANDESCENT BODY FOR ELECTRIC GLOW-LAMPS.

SPECIFICATION forming part of Letters Patent No. 663,095, dated December 4, 1900.

Application filed September 20, 1900. Serial No. 30,620. (No specimens.)

To all whom it may concern.-

Be it known that LALEXANDER J UST, a subject of the Emperor of Austria-Hungary, residing at Vienna, in the Province of Lower Austria, in the Empire of Austria-Hungary, have invented certain new and useful Improvements in Incandescent Bodies for Electrio Glow-Lamps and I do hereby declare the following .to be a full, clear, a nd exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

All proposals and attempts to make incandescent bodies for electric glow-lamps from a mixture of conductors of the first and second classes have, so far as I am aware, given no practically successful result. The conductors of the second class, such as oxids or salts, heretofore used in such mixtures with conductors of the first class-as, for example, carbon-have the disadvantage of being only complete non-conductors when cold, while with increasing temperatures they are converted into comparatively good conductors in not appreciably influenced by increase of temperature. Such bodies according to this invention are made from a mass comprising or containing a conductor or conductors of the first class, especially carbon, boron, or silicon, and the nitrids of boron or silicon r1. 6., boron-nitrid or silicon-nitrid. These nitrids represent conductors of the second class; but they have such a small conductivity even at the highest temperatures occurring in the electric glow-lamp that they may be considered non-conductors.

Of the nitrids mentioned nitrid of boron is of especial value in the manufacture of the incandescent bodies in question in consequence of the ease with which it can be prepared. Furthermore, nitrid of boron fulfils all the requirements of a substance intended for use in electric glow-lamps, as it is infusible at the highest temperatures occurring in such lamps, is non-volatile, and is inert in a high degree.

For the purpose of making such incandescent bodies the nitrid used, preferably boron nitrid, is first mixed in a fine state of division with a conductor of the first classas, for example, carbon in any suitable form, (lampblack, graphite, and the like,) boron, or silicon. The proportions of the substances used may vary, say, from about ten to thirtyfive parts, by weight, of the nitrid to about one part, by weight, of the conductor of the first class employed. To the mixture is added a sufficient quantity of a suitable binding agent-as, for example, hot coal-tarto convert it into a plastic mass from which the incandescent bodies of the desired shape-as, for example, rods, tubes, and the like-are made by molding or otherwise. The pieces of plastic material thus obtained are then embedded while still soft in carbon-powder and are burned out of contact with air. incandescent bodies thus obtained exhibit a sufficient degree of firmness to enable them to be mounted in any desired manner in glass bulbs, which can be afterward exhausted in the usual manner.

I claim 1. An incandescible body composed of an intimate mixture of a conductor of electricity and a refractory nitrid of a metalloid, substantially as set forth.

2. An incandescible body comprising a mixture of nitrid of boron, silicon and a carbonaceous material, substantially as described.

3. An incandescible body comprising a mixture of nitrid of boron and carbon, substantially as set forth.

4.. An incandescible body comprising boron, carbon and nitrid of boron, substantially as set forth.

5. An incandescible body comprising boron, silicon, carbon and a refractory nitrid of a metalloid, substantially as set forth.

In testimony that I claim the foregoing as my invention I have signed my name in pres ence of two subscribing witnesses.

ALEXANDER JUST. Witnesses:

JosEF RiIBANK, ALVESTO S. HOGUE.

The 

